Combined scope and distance finder.



N0. 822,751. PATENTED JUNE 5, 1906.` A T. II. MITCHELL.

COMBINED SCOPE AND. DISTANCE FINDER.

APPLICATION FILED PBB.1.1904.

- tographic views of I miran 'STATES' rArnN'r onirica; r

THOMAS H. MITCHELL, OF NEW YORKyN. Y.

COMBINED s coPE AND DISTANOE FINDER..A

Specicationioi Letters -Patent;

Patented June 5, 1906.

Application lled February 1. 1904. Serial No. 191,631.

strument Called a Combined Scope and Distance Finder in the Art of Photography, of which the following is a description.

The object of the'invention 1s to provide a new andimproved combined-scope and distance finder for use in connection with a photographic camera and arranged to permit the user to quickly and conveniently determine the sco e of the object to be photographed and t e exact focal distance between the camera and the object, to allow quick, convenient, and accurate adjustment of the camera according to the distance lobtained, to produce a sharp focus of rthe object and the subseqpent production of phogh quality and merit. l

The invention consists of novel features and parts and combinations of theA same,

which will be more fully described hereinafter and then pointed out in the claims.

y A practical embodiment of the invention is represented in the accompanying drawings, forming a part of this specification, in

which similar characters of reference indicate corresponding parts inall the views.

lFigure 1 1s a side elevation of the improvement. Fig. 2 is an end view of the eypiece.

Fig. 3 is an end view of the finder. 4 is a longitudinal sectional view of the improvement. Fig. 5 is an end view of the same from the forward end, and Fig. 6 is an enlar ed cross-section of the same.

n the inner end 'of the tubular body A of` the focal distance-finder is mounted to slide len thwise the tubular slide B, and on the tolp of t e forward end of the said tubular bod is xed a block C, supporting the short tu ular body D of the scope-finden The detail construction of the focal distance-finder is as follows: A lsingle planoconvexI objective lens c is mounted on anapertured block d, secured in the forward end of the ltubular body A by set-screws [c and '76,

- the lens abutting against an annular seat or shoulder formed in the wall ofthe o e'ningf of the block d, and the lens is presse againstthe shoulderb as litggvire ring g. A tubular eyepiece-b ook is2 secured by a screw p to the rear or outer end ofthe tubular shde B, -and'in this block is mounted 'the double convex eyepiece-lens J, heldl against. the annular On the outside of thewhen coinciding with the rear edgev of the tubular body A on sliding the slide B correspondingly inward br outward in the tubular body A.` Y

The detail construction of the scope-finder -is as follows: In the front end ofthe tubular body D of the scope-finder is secured a lensblock b the use of screws t, and in the said lens-bloclil is mounted a small double-convex objective lens y', held against an annular seat or shoulder u by a split wire ring k,1o. A ground or objective glassX is permanently attached to a tube y, fitted in the rear end of the body D, and on the rear face of the ground glass X is a rectangular frame or Washer e, having the opposite wallsul a and b b to enable the user to readily determine the scope of the object on the ground glass and irrespective whether the instrument lis held with the scope-finder on top of the focal distance-finder or to one side thereof, as will be readily understood by reference to Figs. 3 an -The operation is as follows: The operator first views the distant object to be subsegently photographed b means of the scopeder on the ground g ass X to determine the size of the image of the object as it appears on the ground glass, and then the operator looks'throu h the distance-finder at' the eyepiece-block and views the image as it appears on the ground glass K, and if the imageldoes not a pear s harply'deflned the operator moves t e slide B inward or outvward until the image appears in vproper and accurate focus on the ground glass K. When this has been obtained, Vthe o erator reads the focal distance on the sca e E, as pre- -fviously explained, and then sets the cameralens correspondingly to the saine gure. Thus by the arrangement described the operator, lby the use of the combined scope and focal distance-finder, can readily, quickly, and accurately determine both the size of the -image of the object aait-appears on the IOC -III

ground glass X of the scope-inder and the distance to which the camera-lens must be 1. Adistance-nder comprising a tubular body, a tubular slide mounted -to slide in the inner end of the said body, an objective mounted in the outer endof the said tubular body, an eye iece mounted in the outer end of said tubu ar slide, and a round glass mounted in the said tubular ide between the eyepieceand the said objective.`

2. A distance-,iinden comprising a tubular body, a tubular slide mounted to slide in the inner end of said body, and havinga distancescale lengthwise on the outer surface thereof,

the marks ofthe scale being read on the inner edge of said tubular body, an objective mounted in the outer end of said tubular objective lens mounted on the outer end of said body, a double convex lens on the outer end of said tubular slide, and a ground glass in the said tubular slide and spaced apart from said double convex lens, the tubular slide having a distance-scale arranged lengthwise on the outside thereof.. In testimony 'whereof I have signed my name to this specification in the presence of two subscribing witnesses. l

THOMAS H. MITCHELL.

lWitnesses: i

WILLIAM GEE WEsTLAKE,Jr., JOHN LAVENDER MITCHELL.' 

